If the US plays its cards well and acts not as
a soloist but as the leader of a concert of nations, the Pax Americana,
in terms of its duration, might become more like the Pax Romana than the
Pax Britannica. If so, our soft power will play a major role. As Henry
Kissinger has argued, the test of history for the US will be whether we
can turn our current predominant power into international consensus and
our own principles into widely accepted international norms. That was
the greatness achieved by Rome and Britain in their times.

Unlike Britain, Rome succumbed not to the rise of a new empire, but to
internal decay and a death of a thousand cuts from various barbarian groups.
While internal decay is always possible, none of the commonly cited trends
seems to point strongly in that direction at this time. At the start of
the century, terrorist threats notwithstanding, American attitudes are
both positive and realistic. The initial response to September 2001 was
encouraging. The public did not turn to isolationism and the Congress
and administration curbed their unilateralism. The public is also realistic
about the limits of American power and expresses a willingness to share.
"While 28 percent say America will remain the major world power in
the next 100 years, 61 percent believe the United States will share this
status with a few other countries. (Fewer than one in 10 thinks the US
will no longer be a major power.)" Large majorities oppose a purely
unilateralist approach. "Upwards of two-thirds of the public oppose,
in principle, the US acting alone overseas without the support of other
countries." The American public seems to have an intuitive sense
for soft power even if the term is unfamiliar.

On the other hand, it is harder to exclude the barbarians. The dramatically
decreased cost of communication, the rise of transnational domains (including
the Internet) that cut across borders, and the democratization of technology
that puts massive destructive power (once the sole preserve of governments)
into the hands of groups and individuals all suggest dimensions that are
historically new. In the last century, men such as Hitler, Stalin and
Mao needed the power of the state to wreak great evil. Such men and women
in the 21st century will be less bound than those of the 20th by the limits
of the state, and less obliged to gain industrial capabilities to wreak
havoc. Clearly the threshold for small groups or even individuals to inflict
massive damage on those they take to be their enemies is falling dramatically.
Countering such terrorist groups must be a top priority. Homeland defense
takes on a new importance and a new meaning and will require an intelligent
combination of hard and soft power. If such groups were to produce a series
of events involving even greater destruction and disruption of society
than occurred in September 2001, American attitudes might change dramatically,
though the direction of the change is difficult to predict. Isolationism
might make a comeback, but greater engagement in world events is equally
plausible.